The following is a tabulation of some prior art that presently appears relevant:
U.S. patentsPat. No.Kind CodeIssue DatePatentee8,321,065B12012 Nov. 27Kirchhof-Falter6,085,218B12000 Jul. 04Carmon7,613,595B12009 Nov. 03MacLay6,189,022B12001 Feb. 13Binns7,302,685B12007 Nov. 27Binns7,140,022B12006 Nov. 21Binns6,964,048B12005 Nov. 08IshamU.S. patent application publicationsPublication Nr.Kind CodePubl. DateApplicant20020138542Al2002 Sep. 26Bollella20090013322Al2009 Jan. 08MacLay20060200795Bl2006 Sep. 07MacLay